I only did that with small stairs in like... highschool. I was like the only person who did it too and one of my acquaintances used to mock me for it. Said I should start screaming while running up the stairs. I wasn't running That would have been funny though. Everyone was scared of me anyway <3

Two at a time coming downstairs is easier if you do it at an angle. Maybe two stairs with the outside foot, one stair with the inside. I'm not sure but I think that's how I did it back then